<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var socket;
    if (window.WebSocket) {
        socket = new WebSocket("ws://localhost:7999/hello")
        //相当于channelReado, ev 收到服务器端或送的消息
        socket.onmessage = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + ev.data;
        }
        //感知连接开启
        socket.onopen = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = "连接开启..."
        }
        //感知连接关闭
        socket.onclose = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + "连接关闭了...";
        }
    } else {
        alert("浏览器不支持")
    }

    //发送消息到服务器
    function send(message) {
        if (!window.socket) {
            return;
        }
        if (socket.readyState == WebSocket.OPEN) {
            socket.send(message)
        } else {
            alert("连接没有开启")
        }
    }
</script>
<form onsubmit="return false">
    <textarea name="message" id="" style="height:300px;width: 300px"></textarea>
    <input type="button" value="发送消息" onclick="send(this.form.message.value)">
    <textarea id="responseText" style="height:300px;width: 300px"></textarea>
    <input type="button" value="清空内容" onclick="document.getElementById('responseText')
.value=''">

</form>
</body>
</html>